package com.hmdp.utils;


import lombok.Data;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

@Data
public class SimpleRedisLock implements ILock {
    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString().replace("-", "")+"-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    private StringRedisTemplate stringRedisTemplate;
    private String name;

    public SimpleRedisLock() {}

    public SimpleRedisLock(String lockName,StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.name = lockName;
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        Boolean isSuccess = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(isSuccess);
    }

    @Override
    public void unlock() {
        //使用lua脚本一次性执行完多条Redis操作,确保执行的一致性
        stringRedisTemplate.execute(UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX+Thread.currentThread().getId()
                );
    }

//    @Override
//    public void unlock() {
//        // 获取线程标示
//        String threadId = ID_PREFIX+Thread.currentThread().getId();
//        // 获取锁中的标示
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
//        // 判断当前锁是否属于该线程
//        if (threadId.equals(id)){
//            // 释放锁
//            stringRedisTemplate.delete(KEY_PREFIX + name);
//        }
//    }
}
